The immediate reaction to Amazon.com‘s (AMZN) fourth-quarter report has been quite positive as it appears that margins improved, despite the fact that the online retailing giant again missed expectations on both the top and bottom lines.

Nonetheless, shares are jumping approximately 10% in the after hours.

AMZN earned 21 cents in the fourth quarter, which fell short of the Zacks Consensus Estimate at 29 cents and was below last year’s 38 cents. This marks the third straight quarter with a negative earnings surprise. Net sales increased 22% from last year to $21.27 billion, but again that was below expectations of $22.3 billion.

However, operating income was up 56% to $405 million.

Looking toward the first quarter of 2013, AMZN forecasted net sales between $15 billion and $16.6 billion, which would grow 14% to 26%. The Zacks Consensus Estimate is at $16.9 billion.

But taking a larger perspective, Amazon has been making a lot of investments for the future, which have been weighing on its margins. This report seems to indicate that the long-promised margin turnaround may finally have begun.

Chief Jeff Bezos stated: “We’re now seeing the transition we’ve been expecting.” He was referring to positive customer responses for categories like eBooks and Kindle. Perhaps investors agree that AMZN has turned a corner and will, therefore, be more forgiving of this earnings miss.

If analysts share the immediate and positive response to this quarterly report, then perhaps Amazon could improve its Zacks Rank #3 (Hold). Earnings estimates for 2013 have been all over the place in the past 60 days. Out of 29 total estimates, six have been revised lower in that time while 4 were raised.